[Bug 2037281] Update Released

[Łukasz Zemczak]

The verification of the Stable Release Update for systemd has completed
successfully and the package is now being released to -updates.
Subsequently, the Ubuntu Stable Release Updates Team is being
unsubscribed and will not receive messages about this bug report.  In
the event that you encounter a regression using the package from
-updates please report a new bug using ubuntu-bug and tag the bug report
regression-update so we can easily find any regressions.

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to systemd in Ubuntu.
https://bugs.launchpad.net/bugs/2037281

Title:
  Shutdown when triggering daemon-reload early in boot

Status in systemd package in Ubuntu:
  Fix Released
Status in systemd source package in Focal:
  Fix Released
Status in systemd source package in Jammy:
  Fix Released

Bug description:
  In Ubuntu Core 20, and Ubuntu Core 22, we are encountering an issue
  where if a service, started earlier than devices are processed by
  udev, does `systemctl daemon-reload`, the system shuts down. This is
  due to devices for mounted filesystem temporarily taken dead, which
  pulls most units down.

  This was fixed by upstream in
  https://github.com/systemd/systemd/pull/23218.

  But this was not backported to the versions used by Ubuntu packages
  for focal and jammy. The needed commit from that PR is the one with
  message `core/device: ignore DEVICE_FOUND_UDEV bit on switching root`.

  This patch applies to 245.4-4ubuntu3.22 (focal) without rebasing
  needed. And I suppose it does also for jammy.

  I have manually tested the fix with Ubuntu Core 20, and this fixes our
  issue.

  We would like this patch to be backported to focal-updates and jammy-
  updates.

  Thank you in advance.

  [ Impact ]

  If a user adds a service that calls `systemctl daemon-reload`, and if
  this service is started before systemd-udevd. And if the initrd is
  systemd (the case of Ubuntu Core), then most service will be stopped
  or cancel, and the machine will mostly shutdown everything and hang.

  The fix has been backported down to 250 upstream. It is already on
  kinetic and later.

  The fix only affects systems where systemd is used in initrd.

  [ Test Plan ]

  On Ubuntu Core 20 (with Core 22 kernel) or on Ubuntu Core 22. Or on
  any system that uses systemd in initrd.

  Add a systemd service that calls `systemctl daemon-reload`.
  The service should have `DefaultDependencies=no` in order to start as soon as possible and be enabled.

  Restart the machine.

  If fix is not applied, after the service is started, most of units
  with be shutdown, and the system will be unusable.

  [ Where problems could occur ]

  This should affect systems with systemd in initrd.

  There are risks on systems that have an udev rule in initrd not
  present in the main system.

  There are risks on systems that use db_persist in initrd where the
  device can potentially get dead state. Though this does not seem to
  happen on Ubuntu Core 22, even though we use db_persist for dev mapper
  devices. Regression is upstream bug #23429. Commits named
  "core/device: device_coldplug(): don't set DEVICE_DEAD" and
  "core/device: do not downgrade device state if it is already
  enumerated" could be applied as well.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/2037281/+subscriptions